In the pivotal phase 3 open-label STOP 301 study (NCT03557333), participants with migraine treated with dihydroergotamine mesylate (DHE) (INP104; Impel Neuropharma, Seattle, CA) administered to the upper nasal cavity experienced pain relief within 2 hours with quick uptake. The delivery device utilizes propellant-enabled POD technology to conveniently and consistently deliver optimal doses of DHE deep into the vascular rich upper nasal space.
After a 28-day screening period, during which baseline frequency of migraine was measured, participants were able to self-administer up to 3 doses of DHE nasally per week (1.45 mg) to treat their migraine attacks. Among the participants, they reported 4,515 migraines total in the study. Within 2 hours of receiving the first dose of DHE, 38% of participants experienced freedom from migraine pain, 52% had freedom from most bothersome migraine symptom (MBS), and 66.3% experienced pain relief. Of the participants, 84% stated the device administering DHE was easy to use and they preferred it over current treatment.
The phase 3 STOP 301 study enrolled 360 participants who had a documented diagnosis of migraine with or without aura, with at least 2 attacks per month for the previous 6 months. The full safety set was comprised of the 354 participants who received at least 1 dose of DHE.. The primary safety set included the 185 participants who took an average of 2 or more DHE treatments per 28-day period during the 24-week treatment period. Of those enrolled, 74% (n=262) of participants completed the 24-week treatment period.
The most common treatment-emergent adverse events (TEAEs) were nasal congestion (15%), nausea (6.8%), nasal discomfort, and unpleasant taste (5.1% each) with all other TEAEs being reported by less than 3% of participants. No treatment related serious adverse events, cardiac TEAEs or deaths were observed in the study.